The common bicycle has been around for about 100 years. During that time, numerous changes have been made to the basic design. The common bicycle has two tires and uses a pedal crank to turn a mounted sprocket. The sprocket drives a chain that is mounted to a transmission (typically another sprocket or series of sprockets) mounted on the rear tire. As the crank is turned, the rear wheel propels the bicycle forward. The rider's arms are typically supported by a set of handlebars that steer the bike. Although this design is popular and works well at a reasonable cost, it is limited in its efficiency and top speed. At best, the standard bicycle can operate at about 40 to 50 miles per hour. Such speeds can be maintained only by an expert rider in excellent physical condition. Even then, such speeds cannot be maintained indefinitely. Most riders can maintain speeds of 15-20 miles per hour. This level of exertion frequently causes the rider to perspire. As such, commuting by bicycle is not a popular option, especially if the commute is more than a few miles.
Overtime, different designs have been developed for bicycle type vehicles. Some of these vehicles have eliminated the sprocket and chain system for a toothed rack and gear system. Also, designs have been developed that use the rider's arms as well as his or her legs to drive the vehicle. The seating arrangements have also been modified to make riding more comfortable and to increase the available leverage. One example of this arrangement is the recumbent cycle, where the rider sits in a reclining position with the legs elevated.
Examples of these designs are found in the following U.S. Pat. No. 1,443,904 teaches a device that has a pivoting arm. The arm is attached to a toothed rack that engages a gear attached to the rear wheels. This vehicle is driven by the arms of the rider by pumping the pivoting arm back and forth. U.S. Pat. No. 1,449,643 shows a toy horse that uses a vertical toothed rack that engages a gear mounted on the rear wheels. The rider sits on a spring loaded seat that pushed down the rack. Foot rests are provided so that the rider can shift his or her weight forward, thereby allowing the seat and the rack to return to their upper positions. By shifting back and forth, the rider can then propel the vehicle forward. Another vehicle that uses a toothed rack is found in U.S. Pat. No. 2,831,703. This device has the rider standing on a pair of pedals that are attached to a pair of curved racks. The pedals are also connected to a pivot point so that as the rider moves his feet in a walking gait, the racks are pulled or pushed forward or back. The racks engage a gear system on the rear wheel that propels the vehicle forwards. Finally, U.S. Pat. No. 3,998,469 shows a bicycle that has a pair of pedals pivoting near the center of the rear wheel to curved vertical racks engage gears on the rear wheel to propel the vehicle. A variation on this system is seen in U.S. Pat. No. 5,236,211 that uses a series of cables to convert vertical motion of the feet into circular motion capable of propelling a vehicle. All of these devices use the legs to operate the vehicle.
Another line of bicycle-type vehicles embodies a structure that utilizes both the hands and the feet to operate the vehicles. This is done by some manner of alternate reciprocating mechanisms. Examples of these designs are found in following U.S. Pat. No. 2,884,259 is a device that uses a standard pedal crank and chain that are ties to a pair of hand levers. The operation drives a main gear that drives the vehicle. The hand levers are directly tied to the pedals with lengths of line. Although this produces some benefit, the operation is awkward and does not lend itself to a positive gain in mechanical advantage. U.S. Pat. No. 3,760,905 teaches a power converter that uses a recumbent design in which the operator sits in a reclining position. The feet operate a pair of pedals that move in a linear plane. The arms operate a pair of levers that reciprocate. According to the design of the invention, as the pedals and levers are manipulated, the gearing charges a number of springs that subsequently release their energy simultaneously into a drive shaft, thereby propelling the vehicle. Besides operating the device as a vehicle, the device can be used for exercise or to operate other machines.
U.S. Pat. No. 4,928,986 teaches a vehicle that uses both foot pedals and a plunger type handle bar for propulsion. The operating mechanism uses cables and chains to connect to a drive shaft that connects to a standard sprocket and chain to drive the rear wheel. The system requires the operator to push and pull the handlebar as well as push foot pedals to drive the vehicle. Since steering is done through the handlebar, this vehicle seems difficult to operate.
Finally, U.S. Pat. No. 5,272,928 teaches another recumbent cycle that has a pair of foot pedals and a single pivoting handlebar. This system also connects to a single chain and sprocket arrangement to drive the vehicle.